Self-Healing Fibre Reinforced Composites via a Bioinspired Vasculature

This paper demonstrates the first steps towards self-healing composites that exploit a design philosophy inspired by the damage tolerance and self-repair functions of bone. Cracking in either fibre reinforced polymers (FRP) or bone, if left unattended, can grow under subsequent cyclic stresses eventually leading to catastrophic failure of the structure. On detection of cracks, an FRP component must be repaired or completely replaced, whereas bone utilises a series of complex processes to repair such damage. Under normal circumstances, these processes allow the skeleton to continually perform over the lifespan of the organism, a highly desirable aspiration for engineering materials. A simple vasculature design incorporated into a FRP via a "lost wax" process was found to facilitate a self-healing function which resulted in an outstanding recovery (>= 96%) in post-impact compression strength. The process involved infusion of a healing resin through the vascule channels. Resin egress from the backface damage, ultrasonic C-scan testing, and microscopic evaluation all provide evidence that sufficient vascule-damage connectivity exists to confer a reliable and efficient self-healing function.